The mechanism of locomotion in animals Azneezal Ar-Rashid Smk Sri Aman 95007 Sri Aman, Sarawak February 2010
Hydrostatic skeleton • Earthworm – Coelom : fluid-filled chamber • Surrounded by : – Circular muscle : » surround the chamber – Longitudinal muscle : » one end to another
• When circular contract, longitudinal relax – Thinner & longer
• When circular relax, longitudinal contract – Shorter & thicker
• Peristaltic waves – Front to end – Contract rhythmically – Bristles : chaetae • Anchor parts – Other parts can be pull
Exoskeleton • Grasshopper – 6 legs – Antagonistic muscles • Flexor • Extensor
Endoskeleton • Fish – Streamlined body shape – Overlapping scales (backwards) – Covered by a slimy coating – Flexible vertebral column – Myotomes • W-shaped muscle – Opposite actions
• Unstable – Yaw : sideways • Dorsal and ventral fins
– Rolling : transverse • Dorsal and ventral fins
– Pitching : vertical • Pelvic and pectoral fins
• Swim bladder – What is that? : • …………………………………………………………
– Function? : • …………………………………………………………